1. Field of the Invention
The present invention relates to batch washing machines.
2. Description of the Prior Art
There is proposed in German Offenlegungsschrift No. 1,964,414 a batch washing machine comprising a horizontal imperforate drum which is divided into individual chambers by a conveyor worm rigidly disposed within it. In the central axis of the drum there is disposed a central pipe carrying washing water, suds, steam and the like and which is subdivided into individual central pipe portions by the helical surface of the conveyor worm, the washing process being carried out by rotating of the drum with an alternating motion, while the laundry can be transported from one chamber into the next chamber by a rotary movement of the drum through 360.degree. in a single direction.
In the machine proposed by German Offenlegungsschrift No. 1,964,414 there are in the helical surface of the conveyor worm, apertures by which the individual chambers are connected to form treatment zones. The detergent solution required for the process is fed to one or other chamber in the treatment zone through the pipe located on the central axis of the drum. The detergent solution moves through the apertures in the helical surface in countercurrent from chamber to chamber, being discharged from the final chamber in the treatment zone (pre-washing zone, final washing zone, rinsing zone). The washing process occurs thereby by an alternating rotary movement of the drum, while transport of the laundry as such is brought about by a rotary movement of the drum in a single direction.
A disadvantage of this known washing machine which operates on the counter-current principle is the lack of detergent solution separation from chamber to chamber as a result of the apertures in the helical surface of the conveyor worm. This washing machine is thus only suitable for continuous operation involving always only one type of laundry requiring to be washed. A simultaneous washing of batches of laundry involving different types of items, for example coloureds and whites, necessitating a complete separation of the detergent solution, is impossible. In practice, however, there is an increasing need for the simultaneous treatment of different types of laundry in one and the same washing process.